It appears that the Dallas Mavericks and Toronto Raptors have successfully recruited the Memphis Grizzlies to help them complete a trade that would eventually route free-agent swingman Shawn Marion to the Mavericks, according to NBA front-office sources.

Yet sources told ESPN.com that the deal, while very far along, has not been finalized and was unlikely to be completed before Thursday at the earliest, with the trade potentially including a fourth team in its final form.

The Mavericks' interest in a sign-and-trade deal for Marion emerged Tuesday but requires Dallas and Toronto to find at least one more team to facilitate the trade because the Raptors can't waive Stackhouse without incurring an extra $2 million in payroll for next season, which would slice into the cap space they have earmarked to sign prized free agent Hedo Turkoglu away from Orlando.

But the Grizzlies' participation would involve Memphis absorbing Stackhouse's $7.25 million contract and buying him out for $2 million before the Aug. 10 deadline in Stackhouse's contract. It's believed that the trade will stipulate that Dallas pays that $2 million to the Grizzlies to cover that expense.